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Unformatted text preview: IEEE Communications Magazine • June 2009 84 0163-6804/09/$25.00 © 2009 IEEE I NTRODUCTION The growing demand for mobile Internet and wireless multimedia applications has motivated the development of broadband wireless-access technologies in recent years. Mobile WiMAX was the first mobile broadband wireless-access solution based on the IEEE 802.16e-2005 stan- dard  that enabled convergence of mobile and fixed broadband networks through a common wide-area radio-access technology and flexible network architecture. The mobile WiMAX air interface utilizes orthogonal frequency division multiple access (OFDMA) as the preferred mul- tiple-access method in the downlink (DL) and uplink (UL) for improved multipath perfor- mance and bandwidth scalability. Since January 2007, the IEEE 802.16 Working Group has embarked on the development of a new amend- ment of the IEEE 802.16 standard (i.e., IEEE 802.16m) as an advanced air interface to meet the requirements of the International Telecom- munication Union — Radiocommunication/ International Mobile Telecommunications (ITU- R/IMT)-advanced for fourth-generation (4G) systems, as well as the next-generation mobile network operators. Depending on the available bandwidth and multi-antenna mode, the next-generation mobile WiMAX will be capable of over-the-air data-transfer rates in excess of 1 Gb/s and sup- port a wide range of high-quality and high- capacity IP-based services and applications while maintaining full backward compatibility with the existing mobile WiMAX systems to preserve investments and continuing to support first-generation products. There are distinctive features and advantages such as flexibility and the extensibility of its physical and medium- access-layer protocols that make mobile WiMAX and its evolution more attractive and more suitable for the realization of ubiquitous mobile Internet access. The next-generation mobile WiMAX will build on the success of the existing WiMAX technology and its time-to-market advantage over other mobile broadband wireless access technologies. In fact, all OFDM-based, mobile broadband access technologies that have been developed lately exploit, enhance, and expand fundamental concepts that were originally uti- lized in mobile WiMAX. The IEEE 802.16m will be suitable for both green-field and mixed deployments with legacy mobile stations (MSs) and base stations (BSs). The backward compatibility feature will allow smooth upgrades and an evolution path for the existing deployments. It will enable roaming and seamless connectivity across IMT-advanced and IMT-2000 systems through the use of appropriate interworking functions. In addi- tion, the IEEE 802.16m system utilizes multi- hop relay architectures for improved coverage and performance. This article briefly describes the salient technical features of IEEE 802.16m and the potential for successful deployment of the next generation of mobile WiMAX in 2011+....
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- Spring '11
- Computer Science, WiMAX, IEEE Communications Magazine, dL dL dL, IEEE 802.16m